Boiler



Dec. 19, 1933. D. H. MAYO 1,939,823

BOILER iled Nov. 1 1930 Patented Dec. 19, 1933 BOILER Dana H. Mayo, Bethlehem, Pa, asslgnor to Fuller Lehigh Company, Fullerton, Pa., a corporation of Delaware Application November 18, 1930 Serial No. 496,384

7 Claim.

This invention relates to a steam generator having water wall tubes and having tubes extending across the furnace of the boiler to op -erate as slag screen tubes and also as cooling tubes for an arch at the upper portion of the furnace. I

The invention will be understood from the description in connection with the accompany- V ing drawing in which Fig. 1 is a vertical section through an illustrative embodiment of the invention and Fig. 2 is a section along the line 2-2 of Fig. 1.

In the drawing reference character 1 indicates a furnace above which a water tube boiler of the Babcock 81 Wilcox type is located. This boiler comprises the usual bank of inclined tubes 2 connected to uptake headers 3 and downtake headers 4. i v V The rear wall of the furnace is provided with 2 0 upwardly extending water wall tubes 5, the lower ends of which are connected to a row of inclined tubes 6 extending across the lower portion of' the furnace. Thelower ends of the tubes 6 are connected to the header 7 and the upper ends of the tubes 5 are connected to the upper header 8. The header 7 isconnected to the water space of the boiler by one ormore downcomers 9 and the header 8 is connected to the steam space of I the boiler by one or more upcomers 10.

- An arch 11 is provided along the upper front portion of the furnace. Burners 12 project fuel through openings in the arch 11. A row of tubes 13 connects the upper header 14 outside of the p furnace to a lower header 16 at the upper end of the row of front water wall furnace-tubes 17.

' The lower ends of the tubes 1'7 are connected to the header 18 which is connected by one or more downcomers 19 to the water space of the boiler in the usual way. The upper header 14 is connected by upcomer tubes 20 to the steam space of the boiler.

One or more recirculating tubes 20' located on the outside of the furnace connects the upw per header 14 to the lower header 18 for water to recirculate through'this tuberor tubes, thus securing rapid enough flow of water through the inclined slag screen tubes 13 to prevent these tubes from being burned out. n

I Alternate tubes of the tubes 13 are bent downwardly Where these tubes extend across the furnace so as to space the tubes farther apart, thus. providing a slag screen to prevent slag from the fuel from reaching the tubes 2. The tubes 13 extend downwardly, as indicated at 21 and '55 thence substantially horizontally,'as indicated at 22 and support the arch through which the burners 12 project the fuel. The tubes 13 may be lined with tile 23 at the nose of the arch, and the portions 22 of the tubes may be bent later- 7 ally to provide spaces for passage of the fuel. 3

In operation water passes through the tubes 9 into the header 7, thence through the tubes 6 and 5, where steam is generated, the steam,- or steam and water, passing into the header 8 and thence through the tubes 10 into the boiler. 53 Also, water passes downwardly through the tubes 19 into the header 18, thence through the tubes 17 and 13 where steam is generated. The steam, or steam and water, passes into the headers 14, thence through the tubes 20 into the boiler. 7012: The tubes 13 not only serve to support and cool the arch, but also serve as a slag screen to protect the tubes 2. These tubes. are subjected to radiant heat from the furnace and aid in caus ing circulation of water through the tubes 17.

I claim:

1. In a boiler, a furnace, a bank of inclined tubes above said furnace, a curved arch at the upper portion of said furnace, slag'screen tubes below said bank bent so as to extend alongsaid 80,.- arch, and water tubes along the front wall of said furnace connected to said slag screen tubes.

2. In a boiler, a furnace, a bank of inclined tubes above said furnace, an arch for said furnace, inclined slag screen tubes below said bank extending along said arch, and upwardly extending water tubes along the front wall of said furnace connected to said slag screen tubes, and a recirculating tube between the upper ends of said inclined tubes and the lower ends of said wall tubes. 7

3. In a boiler, a furnace, a bank of inclined tubes above said furnace, an arch at the upper portion of said furnace, and slag screen tubes belowcsaid bank extending along said arch, a portion of the tubes extending along said arch being horizontal and staggered.

4. In a'boiler, a furnace, a bank of inclined tubes above said furnace, an arch for said furnace, slag screen tubes below said bank extending along said arch, said slag screen tubes being bent below said inclined tubes to form a nose for said arch, tile lining said nose, and water tubes along the front wall of saidfurnace con- 'nected to said slag screen tubes.

5. In a-boiler, a furnace, a furnace arch, a bank of inclined tubes above said furnace, a vertically extending wall below the lower portionsofsaid inclined tubes and above said arch, and 10 ends with the lower ends of said slag screen-,

tubes.

7. In a steam boiler, vertical walls defining a" furnace of substantial height and cross-sectional area, vertical walls defining a gas pass above and of less cross-sectional area than said furnace, a substantially horizontal arch connecting the upper end of one of said furnace walls to the corresponding vertical wall of said gas pass, means for discharging a fluid fuel downwardly through said arch into said furnace, a bank of steam generating tubes in said gas. pass and above said arch, a'row of slag screen tubes extending across said gaspass below said tube bank, and tubes communicating with said slag screentubes and extending downwardly along said corresponding vergtical gas pass wall and having their lower portions bent and extending along the underside of, said'arclr.v

DANA I-I. MAYO. 

